people do it for all kinds of reasons. epilepsy treat is one of them. not everyone does it for weight loss, that's just one of the benefits.
it sounds like you did it without doing any research on the supplements you need, which is what most people do.
a lot of people do it for other health reasons. lower cholesterol, no diabetes, lower blood pressure. it helps a lot of autoimmune disorders. helps women with pcos. the list goes on and on.
diabetes runs in my family, and i'd rather not deal with it, so i stay healthy (or try to) plus, it keeps my binge eating under control.